In order to reduce fuel consumption during operation of a motor vehicle a strategy referred to as “coasting” may be employed. A coasting mode or coasting phase may occur when a driver releases an accelerator pedal of the motor vehicle and a drive train of the motor vehicle is automatically opened. The opening of the drive train may reduce or eliminate transfer of engine torque to the drive train in order to reduce drag. As a result of the drive train being opened, a coasting (or unpowered travel) distance of the motor vehicle may increase drastically. Correspondingly, the increase in the coasting distance of the motor vehicle results in a reduction in fuel consumption. Accordingly, it may be to a driver's benefit to maximize a costing distance traveled by the motor vehicle. Moreover, if a driver is instructed how to increase a coasting distance through operation of the motor vehicle according to a coasting strategy, the driver typically will exhibit driving behavior that results in a reduction in fuel consumption after only a short period of time.
Various strategies have been proposed related to tracking driver behavior. In one example, DE102009037875A1 discloses a method for determining a fuel savings during coasting of a motor vehicle relative to fuel consumption during other operation. In particular, actual fuel consumption is compared with stored values that depend on motor vehicle speed, road gradient, and other operating parameters.
In another example, EP2028058A2 discloses a motor vehicle including a display of information describing driving behavior in relation to fuel consumption. In particular, the driving behavior is characterized by a point scale or assessment scale that assesses how eco-friendly the driving style of the driver is in terms of accelerating, gear shifting and rolling behavior.
In another example, DE102010011088A1 discloses a device for displaying information in a motor vehicle that coaches a driver to optimize their driving style. The information relates to achieving a driving style that reduces fuel consumption and/or emissions of the motor vehicle. In particular, a graphical symbol is displayed in the motor vehicle if an actual value of fuel consumption is less than or greater than a stored base value, and the graphical symbol is enlarged depending on the detected deviations of the actual value from the base value.
However, the inventors herein have identified some potential issues with all of these approaches. For example, none of the approaches disclose the specific concept of motivating a driver of a motor vehicle to increase the use of a “coasting strategy” where the driver lifts their foot off the accelerator pedal in order to allow the drive train to open such that drag of the motor vehicle is reduced and the motor vehicle is allowed to travel unpowered. In another example, the above described approaches require a large variety of additional sensors (e.g., camera-based or GPS-based sensors) and complex network technologies between an infrastructure and the motor vehicle and between multiple motor vehicles, which leads to a comparatively high cost and also to a possible distraction of the driver. In another example, the above described approaches do not lead to a learning effect for the driver or change based on a driver's learning. Rather, the respective control units of the motor vehicle undertake the entire process including the decisions to be made, and merely compare actually values to saved reference values that do not change as the behavior of the driver changes.
Thus, in one example, some of the above issues may be at least partly addressed by a method for assessing a driver's ability to coast in a motor vehicle. The method may include assessing driving behavior of the driver according to a comparison of a current value of a coasting characteristic relative to a reference value. The current value may be determined during operation of the motor vehicle. The reference value of the coasting characteristic may be determined from operation of the motor vehicle during at least one past operating phase or another duration. The method further includes displaying a visualization representative of assessed driving behavior of the driver.
In one example, the coasting characteristic is a coasting distance ratio defined as a ratio of a distance traveled by the motor vehicle while coasting relative to an overall distance traveled by the motor vehicle and the reference value is an average coasting distance ratio for a designated duration or a relative maximum coasting distance ratio achieved by the driver for a designated duration.
In some embodiments, the method further includes presenting a challenge to the driver. The challenge may require the driving behavior of the driver to manipulate the current value of the coasting characteristic to meet challenge criteria.
By assessing the driving behavior of the driver based on a coasting characteristic and providing visual feedback of the assessed driving behavior, the driver may be made aware of and have an understanding of their driving behavior relative to a coasting strategy. Furthermore, by presenting a challenge to the driver that requires the current value of the coasting characteristic to be manipulated to meet challenge criteria, the driver may be motivated to use the “coasting strategy” as substantially as possible. Optimally, the driver may use continuous assessment of his driving behavior in relation to the coasting strategy (in the manner of a training system), whereby the distance traveled by the motor vehicle in the coasting mode can be optimized. Moreover, the current and reference values may be updated or learned over time, such that the assessment changes as the driver's driving behavior changes. In other words, the reference value is not a fixed reference value, but a processed learned value that is driver specific.
It will be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description, which follows. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined by the claims that follow the detailed description. Further, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.